The wide deployment of electromechanical locking devices is in part hampered by the power requirements and size of the actuation mechanisms needed to effect unlocking of such electromechanical locking devices. In order to unlock an electromechanical locking device, the locking device requires an actuator which is operable to move a mechanism within the locking device in response to an electrical signal being received from the locking device's electronic control unit. This electrical signal typically causes the actuator to either release a blocking pin which enables a user to turn or slide a mechanism in order to extract a bolt or it may exert sufficient power to extract the bolt without mechanical assistance from a user's hand. In the latter case, the locking device would typically have to be supplied with external power from a mains power supply which restricts the field of application of such locking devices.
An electromechanical locking device which relies upon the strength of a human hand to extract the lock bolt consumes much less power and can be operated by battery-powered sources thereby widening the field of application of such devices. However, existing electromechanical locking devices typically include a locking mechanism in the form of a blocking device which prevents the mechanical component to which a user has access from moving unless an actuator has received an actuation signal from the control unit of the locking device to release the blocking mechanism. As the blocking mechanism is vulnerable to brute force attack in which sufficient strength may be applied to the lock causing the blocking mechanism to fail, such blocking mechanisms are designed to withstand large external forces and as a result are relatively large and heavy. Consequently, the strength requirements of such blocking mechanisms imposes a burden upon the actuators which are required to release such blocking mechanisms, thereby increasing the actuator size and power consumption. This limits the practicality of using battery powered sources for lock actuation. A further problem with such electromechanical locking devices is related to the time it takes to perform lock actuation. Typically, a user should be able to insert a key and open a lock without perceptible delay. To accomplish this, the actuator needs to be relatively fast in its operation. The actuator must also not stick in the event that the user begins to exert a force against the lock before the actuator has had time to release the lock. Such speed and absence of sticking are difficult to accomplish with a relatively heavy blocking device.
It is an object of the present invention to ameliorate the above-mentioned limitations of electromechanical locking devices.